What is gastric banding?

Laparoscopic adjustable gastric banding (LAGB) is a surgical procedure that involves the placement of an adjustable belt around the upper portion of the stomach using a laparascope. The band is made of silicone and can be tightened by adding saline to fill the band (like blowing air into a doughnut-shaped balloon). The band is connected to a port that is placed under the skin of the abdomen. This port is used to introduce or remove saline into the band.

LAGB ultimately restricts the size of the stomach and the amount of food it can hold. It also slows the passage of food to the intestine. By doing so, signals to the brain from the gut allow for a sensation of fullness and satiety with the consumption of less food. This signal is sent from a small pouch created by the band in the upper stomach. When the pouch fills, the same signal is sent to the brain that occurred previously when the entire stomach filled.

What is a lap band?

The LAP BAND® is a specific device brand name and is made by Allergan Inc. The term is often used in the lay community interchangeable with gastric banding (similar to the way we interchange the brand name Kleenex for facial tissue). There are different sizes and models of the LAP BAND. There are also other companies that make gastric banding devices such as the REALIZE® adjustable gastric band (by Ethicon), the MIDBAND®, and the Heliogast® gastric band (which are not available in the US).

Who are candidates for the lap band system?

Generally, candidates for LAGB have a body mass index over 40 kg/m2, or are more than 45 kilograms over their ideal body weight. LAGB can be performed on a person with a BMI of 35-40 kg/m2 if there are problematic medical conditions that are weight-related, such as high blood pressure (hypertension) ordiabetes.

Most surgeons and programs will want to note a history of failed weight lossin the past using more conventional approaches. The procedure is indicated for adults only, and is not to be performed on those less than 18 years old. All patients must demonstrate an understanding of the procedure, and be willing to adhere to the lifestyle changes that are needed to make this procedure successful. Most large centers have a psychological assessment to assure that this last criteria is met.

LAGB is usually contraindicated if the potential patient has difficulty understanding the procedure, is emotionally unstable, or is dependent on drugs or alcohol. Those potential cases with a history of gastrointestinal problems such as ulcers need to be reviewed carefully. Similarly, those that have underlying medical conditions that make them high risk for surgery- such as heart or lung conditions- may be refused the procedure. Associated with these risks is a BMI of greater than 50kg/m2. In this group, there may be a request to lose weight prior to the procedure (although this seems paradoxical). Again, the risks of the procedure in this subgroup of obese patients may outweigh the benefits of surgery. By dropping the BMI under 50 kg.m2, outcomes may be better.

While there is growing discussion about offering LAGB to those with a BMI of 30-35 who have diabetes, there are no current guidelines to allow for this.

How is the lap band (LAGB) procedure performed?

Lap band or LAGB is a surgical procedure done under full general anesthesia and takes about 1 to 2 hours to perform. It is done using a laparoscopic technique. This involves making 3 to 5 small incisions, each about 1 inch in length. The surgeon inserts a small camera attached to a tube into one of these incisions and views the procedure on a screen. The other incisions allow for the use of surgical instruments and placement of the band. The gastric band is placed around the upper part of the stomach and set into position with sutures. The port is then placed in the wall of the abdomen and sutured in place.

How do I prepare for lap band surgery?

Depending on the surgeon or the program, the preparation for surgery will vary. Many centers like to see a commitment from the patient to the necessary lifestyle changes even before surgery. It may be suggested that the patient start eating 5 to 6 small meals a day to prepare for the changes ahead. It may be recommended to wean off "slippery" high calorie foods such as ice cream or milk shakes (since these will continue to be easily absorbed after the procedure).

If the BMI is greater than 50, or if there are other medical issues, medical risk reduction may be needed preoperatively and should be discussed in detail. In addition, a weight loss of 5% to 10% prior to surgery has been shown to improved post operative outcomes, and may be a goal that your surgeon or preoperative care team will discuss with you.

How long is the recovery after lap band surgery?

Recovery varies with each individual. However, in general, LAGB offers a shorter hospitalization and quicker recovery than gastric bypass procedures. In general, most people can return to work 1 week after surgery (if their job is not too physically demanding). Normal activity can usually resume after 6 weeks. 

What is a lap band fill?

A lap band "fill" is the common term for gastric band adjustments. Once surgery is performed, there is a period of healing that must take place before the first adjustment. Usually, the first fill takes place around 6 to 8 weeks. It involves injecting saline into the port just under the skin which is connected to the band. Prior to this, there may be little change in appetite. Fills are painless and are usually performed by the surgeon who performed the procedure. These adjustments may take place to enhance weight loss, especially if there is a plateau phase in weight loss, and they may to performed to overcome side effects such as nausea and vomiting (in this latter case, the band is loosened).

What can I expect my lifestyle to be after lap band surgery (LAGB)?

Immediately after surgery, there will be some pain and discomfort that can be controlled with medications. This is part of the normal recovery phase after any surgical procedure. After 6 to 8 weeks, one can generally return to normal activities. Weight loss with LAGB is a gradual process. Initially, the weight loss may be more dramatic- say 2 to 3 pounds per week. However, this generally slows to a pound or so weekly over the long-term. Naturally, the food choices made will govern this weight loss rate. After about 18 months, the weight loss tends to slow significantly. The average weight loss for this procedure is 40% of excess body weight in the first year, with an additional 10% to 20% in the second year. Patients are usually asked to keep in contact with their surgeon regularly during this time period as further band adjustments may be needed. 

What are the side effects of lap band surgery (LAGB)?

Side effects include nausea and vomiting, ulceration at the band site, esophageal reflux (indigestion), weight regain, anddehydration. Since this type of surgery is restrictive and does not cause malabsorption of nutrients, vitamin deficiencies are not usually seen. However, many centers recommend multivitamin supplementation. Constipation is commonly encountered.

What are the risks and complications of lap band surgery (LAGB)?

LAGB has a low risk of surgical complications compared to other weight reduction procedures. The mortality (death) rate is about 1 in 2000. There is the possibility of the band slipping or eroding into the stomach and of mechanical malfunction. Other complications may include infection, bleeding, and/orabdominal pain.

What type of surgeon performs lap band surgery (LAGB)?

When choosing a surgeon, it is important to search for one who is a qualified bariatric surgeon. In general, practice makes perfect, and the more surgeries performed the better. A surgeon performing 100 or more procedures annually is likely going to have better outcomes. A surgeon who is part of a clinical team of nutritionists, nurses, psychologists, and physicians in general can provide better counseling and support in the pre- and postoperative period.

Medically reviewed by Martin E Zipser, MD; American board of Surgery

REFERENCES:

Dixon JB., O'Brien PE. Changes in comorbidities and improvements in quality of life after LAP-BAND placement. The American Journal of Surgery, December 2002; Vol 184: pp S51-S54.

Favretti F., Ashton D., Busetto L., Segato G., De Luca M. The Gastric Band: First-Choice Procedure for Obesity Surgery. World Journal of Surgery, October 2009; Vol 33(10): pp 2039-48.

Ren CJ., Horgan S., Ponce J. US experience with the LAP-BAND system. The American Journal of Surgery. December 2002; 184(6B): pp 46S-50S.

Why the Weight Gain?

Obvious reasons for weight gain are taking in more calories than usual or reducing the amount of physical activity in your life. However, some people seem to gain weight even when they are eating and exercising the same as always. Let's look deeper at possible reasons for weight gain.

Part Of Gastric Bypass Benefit Could Be Change In Gut Microbes

A new study suggests some of the weight loss that patients experience after gastric bypass surgery could be a result of changes in the mix of microbes in their gut. The researchers say manipulating microbe populations may offer an alternative treatment for obesity, for instance for patients who can't have gastric surgery.

Lee Kaplan, director of the Obesity, Metabolism and Nutrition Institute at Massachusetts General Hospital (MGH), and colleagues, write about their findings in the 27 March online issue of Science Translational Medicine.

Previous studies have shown that the gut microbes of obese people and rats are different to those of slim individuals. 

And experiments in mice have also demonstrated that transferring samples of gut microbes from obese individuals into germ-free mice causes increase in weight and body fat.

"Our study suggests that the specific effects of gastric bypass on the microbiota contribute to its ability to cause weight loss and that finding ways to manipulate microbial populations to mimic those effects could become a valuable new tool to address obesity," says Kaplan in a statement.

Effects of Gastric Bypass Go Beyond Reducing Food Intake

Gastric bypass refers to a range of surgical procedures that rearrange the stomach and small intestine so they handle food differently. After a gastric bypass the patient's stomach is smaller and the food they eat no longer enters some parts of the stomach and small intestine. 

The result is the patient feels full with less food, and their body can't absorb all the calories from the food they eat.

But curiously, the effects of a gastric bypass go beyond those of just reducing the amount of food the patient can eat.

For instance, if you try to lose weight by dieting, you are likely to feel hungry and less satisfied after eating and crave high-fat and high carbohydrate foods. And your body may undergo metabolic changes that make it stubbornly hang on to that excess weight.

But patients who undergo gastric bypass surgery experience almost the opposite: they report feeling less hungry and more satisfied after eating, and they show more interest and desire for low-calorie foods. Plus they use up more energy after eating, and their hormone levels change to reflect those of appetite and hunger.

Previous studies have show that the mix of microbes in the gut of humans and mice change after gastric bypass surgery, and become more like those seen in slimmer individuals. But what is not clear is whether this is a result of the surgery or the subsequent weight loss.

The Study In Mice

So Kaplan and colleagues decided to investigate how the gut microbes change after bypass surgery. And to find out whether the changes result from the surgery, and how they contribute to the benefits of having the surgery.

For their study they bred obese mice by feeding them a high-fat, high-carbohydrate diet, then put them into three groups. One group underwent a version of a common gastric bypass procedure known as the Roux-en-Y, while the other two had sham operations where some of their gut was cut away then reattached.

One of the groups of mice that had the sham procedure continued on the high-fat, high-carbs diet, while the other group was put on a weight reducing lower calorie diet.

By one week after surgery, the bypass mice were showing significant differences in their gut microbe population. There was a shift toward more of the bacteria found in slim individuals and less of those found in obese individuals.

By three weeks after surgery, the bypass mice had shed 30% of their body weight.

And the two groups of mice who had the sham operations showed no change in their gut microbes, even though the group on the calorie-restricted diet shed the same amount of weight as the bypass mice. 

Tests on the mice's metabolism also showed that the bypass mice were using up more energy than the mice who had the sham operations, even though their physical activity levels were the same.

Kaplan and colleagues then took gut samples from each of the three groups of mice and transferred them into mice that had been bred to have no microbes in their gut.

After two weeks, the germ-free mice that had received gut samples from the bypass mice had shed a significant amount of weight.

But the germ-free mice that received gut samples from the mice that had sham operations (including the group that had lost the same amount of weight as the bypass mice) stayed the same weight.

Clue May Lie In Short-Chain Fatty Acids

The researchers did not investigate how changes in gut microbes cause weight loss, and suggest this is a question that needs to be answered with further studies.

But they did find some clues. For instance, there were differences in the amounts of short-chain fatty acids in the guts of the mice, causing the researchers to wonder if different mixes of microbes process food differently and in such a way that this causes differences in overall metabolism; particularly since we already know short-chain fatty acids help regulate metabolism.

Kaplan, who is also associate professor of Medicine at Harvard Medical School, says we need to find out a lot more about how changes in gut microbes brought about by gastric bypass cause changes in metabolism. 

For instance, gastric bypass surgery results in improvements to diabetes and other metabolic disorders. So to what extent are these improvements the result of changes in gut microbes?

"... and then, we we need to learn if we can produce these effects, either the microbial changes or the associated metabolic changes, without surgery," says Kaplan.

"The ability to achieve even some of these effects without surgery would give us an entirely new way to treat the critical problem of obesity, one that could help patients unable or unwilling to have surgery," he adds.

Funds from the National Institutes of Health and Ethicon Surgical Care helped finance the study.

In another recent study involving gut microbes and the gases they produce, researchers found that a breath test may indicate how susceptible a person is to developing obesity.